As far as I know, once you start to take cash you need a publicans license, or at least a license for off premises sales.
You can swap, but it's probably a grey area, best to just make it for yourself, or check out the setting up a brewery thread, it's expensive and complicated and unless you have a ball of money at your disposal it's unlikely that a bank would forward the necessary bond in this time of recession.
Keep it for yourself and friends and family and swap what you can, but I'd forget the commercial side of things unless you are really wanting to get serious about it.